Power tool feed device



Sept. 9, 1952 T. E. MEAD POWER TOOL FEED DEVICE Filed 4Oct. 4, 1947 n 92 mw 2 5 f 2 I||\| l :zzm Z .17 l 2 .lrll.. l :Il l i i l I I I I I .||I1 r Il ,Hd l ).IL w III TII J 4 f@ Z C f Ja, MM o. Z l, u 5 l 3 Z g M ll Z P. Y 2 |||V||El 1211 T-sl il l J q if j f, illlllll i .1 I 4 b i W j f L w n f Patented Sept. 9, 1952 UNITED STATES PATENT OFFICE POWER TOOL FEEDEVCE TheodoreE. Mead, Wilmette, Ill. Application October 4, 1947, Serial No. 777,991 3 claims. (o1. '1r-33.5)

A further object is to provide mechanism which may be readily attached to the quill of a drill press or to other longitudinally movable portions of a power tool for moving the tool longitudinally in the feed operation. Yet, another object is to provide a power cylinder structure equipped with a clamp means for ready attachment of the cylinder to a longitudinally movable tool, While providing means for accurately controlling the feed of the tool toward the work. Other specific objects and advantages will appear as the specification proceeds.

The invention is illustrated, in a single embodiment, by the accompanying drawing, in which- Figure 1 is a broken side view in elevation of apparatus embodying my invention and illustrated as applied to a drill press; Fig. 2, a view similar to Fig. l but showing the quill of the drill press advanced to a lower position by the feed mechanism; and Fig. 3, a broken longitudinal sectional view of the valve structure which may be employed.

In the illustration given, l designates a drill press of usual and well-known construction. The press is provided with the usual shoulder or arm II, which extends outwardly from a supporting standard and in which is guided the movable 'quill I2. The longitudinally movable quill I2 is provided with a yoke I3, and below the yoke is an adapter I4 receiving the drill bit I5.

In the embodiment of the invention illustrated, I provide a power cylinder casing I6 equipped with a head I'I providing a guide boss I8 for the piston stem I9. The piston stem I9 is connected at its inner end to the usual piston 2Il.

The head I1 is unusual in contour, in that it is provided with a lateral extension 2l recessed to receive the quill I2. The outer end of the recessed extension 2l is closed by a removable clamp 22. Bolts 23 extend through each end of the clamp 22 to engage the U-shaped side walls of the extension 2l and to close such side walls about the quill I2.

The bottom of the cylinder is tapped to receive the threaded end 24 of a needle valve 25. The needle valve 25 is provided with a valve chamber 2B, which communicates through a valve seat 2'I- with a flow passage 28 leading into the cylinder I5. The valve casing is provided with a laterallyextending intake fitting 29, which is carried by means of a flexible conduit 30 to the usual valve which provides for an exhausting of the pressure fluid and for the inlet of pressure fluid, the valvebeing connected to a suitable source of pressure fluid. A suitable valve for the control of the exhausting of pressure fluid from the cylinder I6 and for the establishing of communication between a source of pressure fluid and cylinder I6 is that shown in my l(3o-pending application, Serial No. 614,414, for Valve Structure,y

now Patent No. 2,505,333, issued April 25 1950.

The needle valve 25 may be'of any suitableform or construction. In the illustration given inFig. 3, the valve casing provides a rearwardlyextending threaded passage 3| adapted to threadedly receive a shaft 32. The shaft 32 is Y provided -with a recess 33 at its forward end and has an inwardly-extending flanged end 34.

flanged end 34 of shaft 32. A packing nut 38 may cation, Serial No. 777,992, for Needle Valve Structure, may be employed.

In the operation of the devi-ce, compressed air or other pressure fluid is admitted through a suitable control valveto the inlet conduit 23 of the needle valve. The fluid flows through the valve chamber, valve seat andinto the lower portion of the power cylinder chamber. Since the piston shaft or stem I9 engages the xed shoulder or arm I I of the drill press, the piston is not free to move upwardly but is held in a xed position. The casing I6, however, since it is secured to the movable quill, may move, and as a result, the cylinder casing I6 moves slowly downwardly to a lower position, as indicated in Fig. 2. In Such feeding operation, it is found that air pressure is extremely effective in producing a feeding of the 3 tool with the desired pressure and at the desired speed.

The usual spring structure used within the drill press casing ID retracts the quill I2 upon the exhausting of the power uid from the cylinder I6. When the pressure fluid fed to the valve chamber. 26 is cut on" and the exhaust port opened, as in the usual operation, the pressure fluid ilows back from the cylinder I6 through the valve seat 27 and outwardly through the fitting 29. In this operation, the exhaust is speeded up because the valve 35 is free to move rearwardly a limited distance. On the other hand, when Y pressure fluid is again fed into the valve chamber 26, the iluid carries the valve 25 forwardly to its controlling position with respect to valve seat 2 for the power operation.

The cylinder casing may be attached to the quillI of a rotary drill press, said press being provided with a stationary arm for supporting the longitudinallyemovable quill and said quill being drill press and to other power tools without re'- quiring any change at all in the power tool. The headl1 may be secured to the quill or tube of theI tool by inserting the same around the tool, and the clamp end 22 may then be secured in position. VIn the tool press structure, the U-shaped arms of the extension 2l may be secured-upon the quill above yoke i3 or they may rest upon `the yoke i3' of the quill andiexert downward pressure thereon. In the latter arrangement, the flat extension 2lv bearing against the flat yoke Irsupports the cylinder 2| squarely in position during `the downward feeding of the member l2. The recess of extension 2l snugly receives the quill and rwhen the clamp end 22 is screwed into position it secures the extension tightly to the quill.

The power cylinder structure and attachment therefor, which has beendescribed in connection with a power drill press, may obviously be used with very slight modifications for actuating the movable portion of other tools of many types.

The threaded rod il slid'ably supported in the boss ft2 is equipped at its top with two lock nuts GS and lil which provide a depth-stop-and support a snubber spring Y The snubber springis short and` stiff and will slow down the movement of the drill by absorbing power exerted by the cylinder. Thus, by adjusting thetwo loc-k nuts on the threaded rod provided as a depth-stop, the drill feed will be decelerated asV it breaks through the bottoni of a piece of workthus preventing snagging and injury to the drill. The snubber spring serves an important Lnew purpose when employedV in connection withthe apparatus and with the compressed'air feed structure.

'While in the fcregoingspeciiication I have Aset forth a singlestructure in great detail for the purpose of illustrating my invention, it will `be understood that the details of such structure may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. A feed device for a longitudinally-movable tool supportedin a fixed frame, said longitudinally-movable tool being guided by` a `stationary provided nearits lower end with a yoke, an air cylinder closed at its bottom and provided with an air inlet, means for supplying compressed air to said inlet, a piston slidably mounted in said cylinder,. a long. piston stem secured tov said pisto'nhaving a .pointed outer. end, and a headl providedzwith a guide passage therein for receiving said pistonstemto direct saidouter end freely against the stationary arm` ofY said` press, said head being provided with apair` ofy laterallyextending and spaced-apart` ar-ins resting upon and engagingsaidyoke wherebyupon the upward movement` of.` said pistonstem bearingy against said. stationary arm, said yoke andquill are caused to move downwardly. l

3; A feed 'device for a longitudinallymovable tool supporte'din axed. frame, said longitudinally-movable tool being guided for vertical movement in a stationary horizontal supporti-ng arm ofthe frame, saidy longitudinally-movable tool being provided' witha yoke providing hori zontal shoulders, a` cylinder closed atits' bottom and provided atv its bottom with van air inlet, means for supplyinglcompressed air to said inlet and Vfor exhausting said 'air therefrom, an'diarhead closing the top ofA said cylinder Vand yprovided with aA guide lboss having a passage therethrough, said head being provided with a pair of Vlaterallyextending integralarms .resting upon thelshoulders of vsaid yoke and on either side ofV saidlongitudinallyemovable tool, a piston'slidablylmounted in Vsaid cylinder provided with a stem extending through said 'guide boss. and having a rounded tip freely engaging an under surface of.A said` supporting arm.

THEoDoR-E vivinA-n REFERENCES CITED The following. references are of record! in the iil'e of this patent:V v-

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